1. Field of the Invention
The disclosure relates to ceramic composites and, more particularly, the disclosure relates to refractory ceramic composites and methods of making.
2. Description of Related Art
Advanced propulsion and combustion applications require materials with thermal and compositional stability when exposed, in use, to aggressive environments above 1200 degrees Celsius (C.).
Refractory metal carbides, borides, oxides, nitrides, silicides and combinations thereof are particularly suitable materials because they can exhibit one or more of the following beneficial properties at high temperatures: relatively high strength, low density, tailorable thermal conductivity, electrical resistivity and oxidative resistance, controlled thermal expansion, etc. The specific property target values are selected based on the environmental conditions and the needs of the particular application.
Typical applications for refractory ceramic composites include, but are not limited to, thermal protection systems (TPS), insulation, erosion resistant structures, impact resistant structures, heat exchangers, catalytic devices or supports, and structural components. For some of these applications, controlled composition and porosity within a refractory structure enables beneficial thermal stability, weight reduction, strength-to-weight ratio or a superior flow field for cooling fluids with lower pressure drop.
However, preparation of such refractory ceramic composites is difficult, and frequently leads to unacceptable composition, pore structure or undesirable processing difficulties. For example, an unacceptable composition due to processing problems may result in the presence excess silicon carbide (SiC), carbon, and/or refractory metal, none of which may be desirable for a targeted application.
Accordingly, it has been determined by the present disclosure that there is a need for refractory ceramic composites and methods of making such composites that overcome, alleviate, and/or mitigate one or more of the above and other deleterious effects of prior art composites and methods.